The present invention relates to cosmetic and/or dermatological compositions for artificially coloring the skin, which comprise, in a cosmetically acceptable support, at least one compound capable of screening out ultraviolet radiation and at least one flavylium salt compound which is unsubstituted in position 3, and which is substituted with at least one radical chosen from hydroxyl and alkoxy radicals, wherein the at least one flavylium salt compound may be obtained, for example, in a manner chosen from synthetically, from a plant extract containing it, and from an enriched plant extract containing it.
The invention also relates to the use of these compositions for coloring the skin.
Nowadays, it is important to look healthy, and a tanned skin is always a sign of good health. However, a natural tan may not always be desirable since it requires long exposure to UV radiation, for example, to UV-A radiation which causes tanning of the skin. UV-A radiation is also liable to induce an adverse change of the skin, for example, in the case of sensitive skin and of skin which is continually exposed to solar radiation. It is thus desirable to find an alternative to a natural tan which may be compatible with the requirements of such skin types.
Most of the cosmetic products intended for artificially tanning the skin are based on monocarbonyl and polycarbonyl compounds which, by interacting with the amino acids in the skin, allow the formation of colored products.
To this end, it is known that dihydroxyacetone (xe2x80x9cDHAxe2x80x9d), is a product which is commonly used in cosmetics as an agent for artificially tanning the skin. When applied to the skin, for example, to the face, it gives a tanning or bronzing effect which may be similar in appearance to that which may result from prolonged exposure to sunlight (a natural tan) or under a UV lamp.
One drawback of DHA can be the length of time the coloration takes to develop. Specifically, several hours (3 to 5 hours in general) may be required for the coloration to be revealed.
Furthermore, DHA can have an annoying tendency, which is more or less pronounced depending on the nature of the medium in which it is formulated, to degrade over time. This degradation is generally reflected in the long run by an undesirable yellowing of the compositions containing it. The result of such a phenomenon is that the activity of DHA, such as its ability to color the skin, may be reduced when these compositions are applied to the skin. Thus, the intensity of the coloration and the staying power of the coloration over time that are obtained on the skin may be unsatisfactory.
Thus, efforts are still under way to find novel compounds and novel compositions which can give the skin an artificial coloration, for example, close to that of a natural tan in at least one of a simple, effective, fast and risk-free manner. It is also sought to obtain a coloration which is at least one of more homogeneous and longer-lasting.
Anthocyanin colorants have been known for a long time as pharmaceutical and food colorants. These anthocyans may be present in nature in the form of heterosides known as anthocyanosides and genins, known as anthocyanidines. These anthocyans may be phenyl-2-benzopyrylium derivatives and flavylium derivatives and may be present, for example, in plants in the form of salts. Anthocyans may be red-, violet- and blue-colored compounds which generally color flowers, fruit and occasionally leaves. The color observed may depend both on the structure of the predominant genin and on the conditions of the medium in which the anthocyanin colorants are present.
Now, after considerable research conducted in the field of artificial coloring of the skin, the Inventorss have discovered that the combination of at least one agent for screening UV radiation chosen from organic and mineral agents and of at least one flavylium salt compound unsubstituted in position 3, may, for example, immediately give the skin, after the product has been applied thereto, an artificial coloration, for example, close to that of a natural tan. Furthermore, the said combination may make it possible to obtain a shade which is is at least one of more uniform and longer-lasting than a self-tanning agent of the carbonyl type, such as DHA.
One subject of the present invention is thus novel cosmetic and/or dermatological compositions for giving the skin an artificial coloration, for example, close to that of a natural tan, comprising, in a cosmetically acceptable support, at least one agent for screening out UV radiation chosen from organic and mineral agents and at least one flavylium salt compound which is unsubstituted in position 3, and which is substituted with at least one radical chosen from hydroxyl and alkoxy radicals, wherein the at least one flavylium salt compound may be, for example, obtained in a manner chosen from synthetically, from a plant extract containing it, and from an enriched plant extract containing it.
Another subject of the present invention is the novel use of the combination of at least one agent for screening out UV radiation chosen from organic and mineral agents and of at least one flavylium salt compound which is unsubstituted in position 3, and which is substituted with at least one radical chosen from hydroxyl and alkoxy radicals, wherein the at least one flavylium salt compound may be obtained, for example, in a manner chosen from synthetically, from a plant extract containing it, and from an enriched plant extract containing it, in cosmetic and/or dermatological compositions, with the aim of giving the skin an artificial coloration, for example, close to that of a natural tan.
A subject of the present invention is also a process for giving the skin an artificial coloration, for example, close to that of a natural tan, comprising applying to the skin an effective amount of the combination of at least one agent for screening out UV radiation chosen from organic and mineral agents and of at least one flavylium salt compound which is unsubstituted in position 3, and which is substituted with at least one radical chosen from hydroxyl and alkoxy radicals, wherein the at least one flavylium salt compound may be obtained, for example, in a manner chosen from synthetically, from a plant extract containing it, and from an enriched plant extract containing it.
The compositions and uses in accordance with the invention may make it possible to obtain an artificial coloration, for example, close to that of a natural tan, in a very short space of time. Thus, an immediate coloration may be obtained, which may allow at least one of the following properties: visualization of the application, and better homogeneity in the spreading of the composition on the skin and thus of the resulting coloration. Furthermore, the artificial coloration obtained on the skin according to the invention may be extremely close to that of a natural tan.
For the purposes of the present invention, the expression xe2x80x9ccomposition intended for artificially coloring the skinxe2x80x9d will be understood to mean a formulation with a particular affinity for the skin which allows it to give the skin a long-lasting coloration, which may be at least one of non-covering (that is to say which does not have a tendency to opacify the skin), not removed with at least one of water and solvents, and able to withstand both rubbing and washing with a solution containing surfactants. Such a long-lasting coloration may thus be distinguished from the superficial and transient coloration provided, for example, by a make-up product.
At least one other characteristic, aspect and advantage of the present invention may become apparent on reading the detailed description which follows.
The compositions in accordance with the present invention can, for example, generally lead, 30 minutes after application to a fair skin at a rate of 2 mg/cm2, to a darkening characterized in the (L*, a*, b*) colorimetric measuring system by a xcex94L* ranging from xe2x88x920.5 to xe2x88x9220. For example, xcex94L* may range from xe2x88x920.5 to xe2x88x9215.
The compositions in accordance with the present invention can, for example, give, 30 minutes after application to the skin at a rate of 2 mg/cm2, a coloration on a fair skin, defined in the (L*, a*, b*) calorimetric measuring system by a ratio xcex94a*/xcex94b*, ranging from 0.5:1 to 3:1, for example, ranging from 0.8:1 to 2:1.
According to the present invention, the term xe2x80x9cfair skinxe2x80x9d should be understood to indicate an untanned skin whose colorimetric characteristics may be defined by its ITA angle as defined in the publication by A. Chardon et al., xe2x80x9cSkin Color Typology and Suntanning Pathwaysxe2x80x9d presented at the 16 th IFSCC congress, Oct. 8-10, 1990, New York, and in Int. J. Cosm. Sci. 13 191-208 (1991), the disclosures of both references relating to such calorimetric characteristics are herein incorporated by reference. The fair skin as defined in this classification may have an ITA angle of from 35 to 55.
In the (L,* a,* b*) colorimetric measuring system: L* is luminance or clarity, a* is the red-green axis (xe2x88x92a*=green,+a*=red) and b* is the yellow-blue axis (xe2x88x92b*=blue,+b*=yellow). Thus, a* and b* express the shade of the skin.
xcex94L* reflects the darkening of the color: the more negative the xcex94L*, the darker the color becomes, with:
xcex94L*=L* uncolored skinxe2x88x92L* colored skin
The ratio xcex94a*/xcex94b* reflects the red/yellow balance and thus the shade, with:
xcex94a*=a* uncolored skinxe2x88x92a* colored skin
xcex94b*=b* uncolored skinxe2x88x92b* colored skin
The at least one flavylium salt compounds which may be unsubstituted in position 3 include, for example, those corresponding to formula (I) below: 
wherein:
R1 is chosen from OH and linear and branched, saturated and unsaturated (C1-C8) alkoxy radicals,
R2, R3 and R4, which may be identical or different, are chosen from H and R1, it being understood that, for example, in one embodiment of the invention, at least one of the radicals R1 to R4 is OH,
Xxe2x88x92 is chosen from organic ions and mineral anions. For example, Xxe2x88x92 can be chosen from anions derived from mineral acid derivatives, and can be chosen from, for example, halides, such as, for example, bromide and chloride. As another example, Xxe2x88x92 can be chosen from an anion derived from an organic acid, and can be chosen from, for example, acetate, borate, citrate, tartrate, lactate, bisulphate, sulphate, and phosphate.
The at least one flavylium salt compounds of formula (I) may be, according to the present invention, chosen from the group for which, in formula (I), R1 is chosen from OH and OCH3.
Among these, mention may be made, for example, of the chlorides of the following compounds:
4xe2x80x2,5,7-trihydroxyflavylium, commonly known as xe2x80x9capigeninidine chloridexe2x80x9d,
3xe2x80x2,4xe2x80x2,7-trihydroxyflavylium,
4xe2x80x2-hydroxyflavylium,
4xe2x80x2,7-dihydroxyflavylium,
3xe2x80x2,4xe2x80x2-dihydroxyflavylium,
3xe2x80x2,4xe2x80x2-dihydroxy-7-methoxyflavylium,
3xe2x80x2,4xe2x80x2,5,7-tetrahydroxyflavylium,
3xe2x80x2,4xe2x80x2,5xe2x80x2,5,7-pentahydroxyflavylium.
For example, the at least one flavylium salt compound may be chosen from at least one of apigeninidine chloride (4xe2x80x2,5,7-trihydroxyflavylium chloride) and 3xe2x80x2,4xe2x80x2,7-trihydroxyflavylium chloride. These compounds can be prepared in pure form, i.e., in a form at least 90% pure
According to certain embodiments, the present invention comprises using apigeninidine chloride in the form of, or derived from, a plant extract, which can be readily prepared by extraction and isolation from leaves of Sorghum caudatum according to, for example, at least one of the processes disclosed in patents CN 1,064,284A and CN 1,035,512C, the disclosures in both patents directed to said extraction and/or isolation are hereby incorporated by reference, and variants of these processes.
According to certain embodiments, the at least one flavylium salt compound may be chosen from those extracted from at least one of the stems, seeds, and leaves of Sorghum bicolour; the petals of Gesneria fulgens; and at least one of the species Blechum procerum and Sorghum in combination with Colletotrichum graminicola. 
According to certain embodiments, the present invention comprises using an extract from the leaves of Sorghum bicolour, which can be obtained by an aqueous-alcoholic extraction in acidic medium at an extraction temperature ranging from 30 to 40xc2x0 C. with a ratio of the volume of solvent to the mass of Sorghum bicolor leaves ranging from 10:1 to 30:1. The Sorghum plant extract can have an approximate titre ranging from 0.05% to 50% by weight of apigeninidine chloride.
The at least one flavylium salt compound which is unsubstituted in position 3 and which is substituted with at least one radical chosen from hydroxyl and alkoxy radicals, may be readily and/or cheaply obtained by synthesis, for example, by the well-known method of R. Robinson and D. Pratt, J. Chem. Soc. 745 (1923), the disclosure of which directed to said synthesis is hereby incorporated by reference. The method comprises condensing at least one of an ortho-hydroxybenzaldehyde and a substituted ortho-hydroxybenzaldehyde with at least one of an acetophenone and a substituted acetophenone to yield, by selecting the substituents, a desired at least one flavylium salt compound, corresponding to formula (I).
Taking apigeninidine chloride (4xe2x80x2,5,7-trihydroxy-flavylium chloride) as an example, the synthetic scheme (i) may be as follows: 
Taking 3xe2x80x2,4xe2x80x2,7-trihydroxyflavylium chloride as an example, the synthetic scheme (ii) may be as follows: 
A variety of synthetic routes, for example those that are well known in the field, may be used to lead to apigeninidine.
One method for preparing apigeninidine comprises, for example, in a first step, preparing trimethylapigeninidine by condensing commercial 4,6-dimethoxy-2-hydroxybenzaldehyde with commercial 4-methoxyacetophenone in an anhydrous ether medium at 0xc2x0 C., and saturating with anhydrous HCl, to yield, after filtration, an orange-red precipitate of trimethylapigeninidine. In a second step, the trimethylapigeninidine obtained in the preceding step is hydrolyzed to apigeninidine chloride, the reaction being carried out in a medium of Hl and phenol and AgCl dissolved in methanol. Such a synthetic method is disclosed for example, by R. Robinson and A. Robertson in J. Chem. Soc. 1951 (1926) and 2196 (1927), the disclosure of which directed to said synthesis is incorporated herein by reference.
Another method, for example, for preparing apigeninidine comprises condensing 2,4,6-trihydroxybenzaldehyde with 4-hydroxyacetophenone at 0xc2x0 C. in an anhydrous solvent medium, for example ethyl acetate, and saturating with anhydrous HCl, to yield apigeninidine chloride. Such a method is disclosed, for example, by R. Robinson and A. Robertson in J. Chem. Soc. 1528 (1928), the disclosure of which directed to said synthesis is hereby incorporated by reference.
Another method, for example, for preparing apigeninidine chloride comprises reducing at least one of a flavone, naringenin, and triacetyl derivatives thereof, with NaBH4, and then oxidizing the product obtained with chloranil (tetrachloro-1,4-benzoquinone). The method is disclosed, for example, by J. G. Sweeny and G. A. Iacobucci in the review Tetrahedron 33 2923-2927 (1977), the disclosure of which directed to said synthesis is hereby incorporated by reference.
As a further example, use may be made of a method comprising condensing 2,4-dihydroxy-6-benzoyloxybenzaldehyde with 4-hydroxyacetophenone at 0xc2x0 C. in an anhydrous ethyl acetate medium, saturating with anhydrous HCl and then debenzoylating the product obtained with sodium hydroxide, to yield apigeninidine chloride in high yield, according to scheme (i) described above. The method is disclosed, for example, by R. Robinson and J. C. Bell in J. Chem. Soc. 813 (1934), the disclosure of which directed to said synthesis is hereby incorporated by reference.
The concentration of the at least one flavylium salt compound as described according to the present invention may generally range, for example, from 0.0001% to 10%, such as, for further example, from 0.001% to 5%, by weight relative to the total weight of the composition.
The composition of the present invention may contain at least one agent for screening out ultraviolet radiation, wherein said at least one agent may be chosen from organic UV screening agents and mineral agents.
The organic UV screening agents in accordance with the invention may be chosen from water-soluble agents, liposoluble agents and agents which are insoluble in usual cosmetic solvents. These agents may be chosen from, for example, anthranilates; cinnamic derivatives; dibenzoylmethane derivatives, salicylic derivatives; camphor derivatives, triazine derivatives such as those disclosed in patent applications U.S. patent application Nos. 4,367,390, EP 863145, EP 517104, EP 570838, EP 796851, EP 775698, EP 878469 and EP 933376, the disclosures of each of which relating to UV screening agents are herein incorporated by reference; benzophenone derivatives; xcex2,xcex2xe2x80x2-diphenylacrylate derivatives, benzotriazole derivatives, benzimidazole derivatives; imidazolines; bisbenzazolyl derivatives such as those disclosed in patents EP 669 323 and U.S. Pat. No. 2,463,264, the disclosures of both of which are herein incorporated by reference; p-aminobenzoic acid (PABA) derivatives; methylene bis(hydroxyphenylbenzotriazole) derivatives such as those disclosed in patent applications U.S. Pat. No. 5,237,071, U.S. Pat. No. 5,166,355, GB 2 303 549, DE 19 726 184 and EP 893 119, the disclosures of each of which are herein incorporated by reference; screening polymers and screening silicones such as those disclosed in patent application WO 93/04665, the disclosure of which is herein incorporated by reference; dimers derived from xcex1-alkylstyrene, such as those disclosed in patent application DE 19 855 649, the disclosure of which is herein incorporated by reference; 4,4-diarylbutadiene derivatives such as those disclosed in patent applications EP 0 967 200 and DE 19 755 649, the disclosures of both of which are herein incorporated by reference.
Examples of the at least one organic screening agent, denoted hereinabove by their INCI name, include:
Para-aminobenzoic acid derivatives
PABA,
Ethyl PABA,
Ethyl dihydroxypropyl PABA,
Ethyihexyl dimethyl PABA sold, for example, under the name xe2x80x9cEscalol 507xe2x80x9d by ISP,
Glyceryl PABA,
PEG-25 PABA sold under the name xe2x80x9cUvinul P25xe2x80x9d by BASF,
Salicylic derivatives
Homosalate sold under the name xe2x80x9cEusolex HMSxe2x80x9d by Rona/EM Industries,
Ethyl hexyl salicylate sold under the name xe2x80x9cNeo Heliopan OSxe2x80x9d by Haarmann and Reimer,
Dipropylene glycol salicylate sold under the name xe2x80x9cDipsalxe2x80x9d by Scher,
TEA salicylate sold under the name xe2x80x9cNeo Heliopan TSxe2x80x9d by Haarmann and Reimer,
Dibenzoylmethane derivatives
Butyl methoxydibenzoylmethane sold, for example,under the trade name xe2x80x9cParsol 1789xe2x80x9d by Hoffmann-La Roche,
Isopropyidibenzoylmethane,
Cinnamic derivatives
Ethyihexyl methoxycinnamate sold, for example,under the name xe2x80x9cParsol MCXxe2x80x9d by Hoffmann La Roche,
Isoproyl methoxycinnamate,
Isoamyl methoxy cinnamate sold under the trade name xe2x80x9cNeo Heliopan E 1000xe2x80x9d by Haarmann and Reimer,
Cinoxate,
DEA methoxycinnamate,
Diisopropyl methylcinnamate,
Glyceryl ethylhexanoate dimethoxycinnamate
xcex2,xcex2xe2x80x2-diphenylacrylate derivatives
Octocrylene sold, for example, under the trade name xe2x80x9cUvinul N539xe2x80x9d by BASF,
Etocrylene, sold, for example, under the trade name xe2x80x9cUvinul N35xe2x80x9d by BASF,
Benzophenone derivatives
Benzophenone-1 sold under the trade name xe2x80x9cUvinul 400xe2x80x9d by BAS F,
Benzophenone-2 sold under the trade name xe2x80x9cUvinul D50xe2x80x9d by BAS F,
Benzophenone-3 or Oxybenzone, sold under the trade name xe2x80x9cUvinul M40xe2x80x9d by BASF,
Benzophenone-4 sold under the trade name xe2x80x9cUvinul MS40xe2x80x9d by BAS F,
Benzophenone-5
Benzophenone-6 sold under the trade name xe2x80x9cHelisorb 11xe2x80x9d by Norquay
Benzophenone-8 sold under the trade name xe2x80x9cSpectra-Sorb UV-24xe2x80x9d by American Cyanamid
Benzophenone-9 sold under the trade name xe2x80x9cUvinul DS-49xe2x80x9d by BASF,
Benzophenone-12
Benzylidene camphor derivatives
3-Benzylidene camphor manufactured under the name xe2x80x9cMexoryl SDxe2x80x9d by Chimex,
4-Methylbenzylidene camphor sold under the name xe2x80x9cEusolex 6300xe2x80x9d by Merck,
Benzylidenecamphorsulphonic acid manufactured under the name xe2x80x9cMexoryl SLxe2x80x9d by Chimex,
Camphor benzalkonium methosulphate manufactured under the name xe2x80x9cMexoryl SOxe2x80x9d by Chimex,
Terephthalylidenedicamphorsulphonic acid manufactured under the name xe2x80x9cMexoryl SXxe2x80x9d by Chimex,
Polyacrylamidomethylbenzylidenecamphor manufactured under the name xe2x80x9cMexoryl SWxe2x80x9d by Chimex,
Phenylbenzimidazole derivatives
Phenylbenzimidazolesulphonic acid sold, for example, under the trade name xe2x80x9cEusolex 232xe2x80x9d by Merck,
Benzimidazilate sold under the trade name xe2x80x9cNeo Heliopan APxe2x80x9d by Haarmann and Reimer,
Triazine derivatives
Anisotriazine sold under the trade name xe2x80x9cTinosorb Sxe2x80x9d by Ciba-Geigy,
Ethylhexyltriazone sold, for example, under the trade name xe2x80x9cUvinul TI 50xe2x80x9d by BASF,
Diethylhexylbutamidotriazone sold under the trade name xe2x80x9cUvasorb HEBxe2x80x9d by Sigma 3V,
Phenylbenzotriazole derivatives
Drometrizole trisiloxane sold under the name xe2x80x9cSilatrizolexe2x80x9d by Rhodia Chimie,
Methylenebis(benzotriazolyl)tetramethylbutylphenol, sold in solid form under the trade name xe2x80x9cMixxim BB/100xe2x80x9d by Fairmount Chemical and in micronized form at an aqueous dispersion, under the trade name xe2x80x9cTinosorb Mxe2x80x9d by Ciba Specialty Chemicals,
Anthranilate derivatives
Menthyl anthranilate sold under the trade name xe2x80x9cNeo Heliopan MAxe2x80x9d by Haarmann and Reimer,
Imidazoline derivatives
Ethylhexyldimethoxybenzylidenedioxoimidazoline propionate,
Benzylmalonate derivatives
Polyorganosiloxane containing benzalmalonate functions, sold under the trade name xe2x80x9cParsol SLXxe2x80x9d by Hoffmann La Roche.
For example, the at least one organic UV screening agent may be chosen from the following compounds:
Ethylhexyl salicylate,
Butyl methoxydibenzoylmethane,
Ethylhexyl methoxycinnamate,
Octocrylene,
Phenylbenzimidazolesulphonic acid,
Terephthalylidenedicamphorsulphonic acid,
Benzophenone-3,
Benzophenone-4,
Benzophenone-5,
4-Methylbenzylidenecamphor,
Benzimidazilate,
Anisotriazine,
Ethylhexyltriazone,
Diethylhexylbutamidotriazone,
Methylenebis(benzotriazolyl)tetramethylbutylphenol, and
Drometrizole trisiloxane.
The mineral screening agents are generally chosen from pigments and nanopigments (average size of the primary particles: generally range from 5 nm to 100 nm, for example, such as from 10 nm to 50 nm) of coated and uncoated metal oxides, such as, for example, nanopigments of titanium oxide (amorphous form, crystallized in rutile form, and crystallized in anatase form), of iron oxide, of zinc oxide, of zirconium oxide and of cerium oxide, which are all UV stabilizers that are well known per se. Conventional coating agents may be, for example, chosen from alumina and aluminium stearate. Such coated and uncoated metal oxide nanopigments are disclosed, for example, in patent applications EP-A-0 518 772 and EP-A-0 518 773, the disclosures of which related to said nanopigments are herein incorporated by reference.
The radiation-screening agents may generally be present in the compositions according to the invention in proportions generally ranging from, for example, 0.1% to 20% by weight relative to the total weight of the composition, for further example, such as from 0.2% to 15% by weight relative to the total weight of the composition.
The compositions in accordance with the present invention may also comprise at least one conventional cosmetic adjuvant chosen, for example, from fatty substances, organic solvents, ionic and nonionic thickeners, softeners, antioxidants, free-radical scavengers, opacifiers, stabilizers, emollients, silicones, xcex1-hydroxy acids, antifoams, moisturizers, vitamins, fragrances, preserving agents, surfactants, fillers, polymers, propellants, acidifying and basifying agents, colorants and any other ingredient usually used in cosmetics and dermatology, such as, for example, in manufacturing antisun compositions in the form of emulsions.
At least one fatty substance may be chosen from oils and waxes. The term xe2x80x9coilxe2x80x9d means a compound which is liquid at room temperature. The term xe2x80x9cwaxxe2x80x9d means a compound which is solid or substantially solid at room temperature and whose melting point is generally greater than 35xc2x0 C.
Examples of oils include mineral oils (paraffin); plant oils (sweet almond oil, macadamia oil, blackcurrent seed oil, jojoba oil); synthetic oils such as perhydrosqualene, fatty alcohols, fatty acids and fatty esters (such as the C12-C15 alkyl benzoate sold under the trade name xe2x80x9cFinsolv TNxe2x80x9d by the company Finetex, octyl palmitate, isopropyl lanolate, triglycerides including those of capric/caprylic acid), oxyethylenated and oxypropylenated fatty esters and ethers; silicone oils (cyclomethicone and polydimethylsiloxanes (xe2x80x9cPDMSsxe2x80x9d)) and fluoro oils, and polyalkylenes.
Examples of waxy compounds include paraffin, carnauba wax, beeswax and hydrogenated castor oil.
Examples of organic solvents include lower alcohols and polyols.
According to one embodiment, the compositions according to the invention may contain at least 5% by weight, relative to the weight of the composition, of at least one polyhydroxylated solvent. These solvents may be chosen from glycols and glycol ethers, for instance ethylene glycol, propylene glycol, butylene glycol, dipropylene glycol and diethylene glycol. For example, the compositions according to the invention may contain a mixture of at least three different polyhydroxylated solvents, such as, for example, a mixture comprising propylene glycol, butylene glycol and dipropylene glycol.
The thickeners may be chosen, for example, from crosslinked polyacrylic acids, modified guar gums, unmodified guar gums and celluloses, such as hydroxyprolyl guar gum, methylhydroxyethylcellulose and hydroxypropylmethylcellulose.
Needless to say, a person skilled in the art will take care to select the optional additional compound(s) mentioned above and the amounts thereof such that at least one advantageous property that can be associated with the combination in accordance with the invention is not, or is not substantially, adversely affected by the addition(s) envisaged.
The composition according to the invention may be prepared according to the techniques that are well known to those skilled in the art, for example, such as those intended for preparing oil-in-water and water-in-oil emulsions.
The compositions of the present invention may be, for example, in at least one form chosen from simple and complex (O/W, W/O, O/W/O or W/O/W) emulsions (such as creams and milks), gels, cream-gels, lotions, powders, solid tubes, aerosols, mousses and sprays.
When the composition of the present invention comprises an emulsion, the aqueous phase of this emulsion may comprise a nonionic vesicular dispersion prepared according to known processes, such as is disclosed in Bangham, Standish and Watkins, J. Mol. Biol. 13, 238 (1965), FR 2 315 991 and FR 2 416 008, the disclosures of each of which relating to such emulsions are herein incorporated by reference.
Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term xe2x80x9caboutxe2x80x9d. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Non-limiting examples illustrating the invention will now be given.